Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Lymphoma occurs when lymphocytes, a type of white blood cell, grow abnormally. The body has two main types of lymphocytes that can develop into lymphomas: B-lymphocytes (B-cells) and T-lymphocytes (T-cells). Cancerous lymphocytes can travel to many parts of the body, including the lymph nodes, spleen, bone marrow, blood or other organs, and can accumulate to form tumors. Peripheral T-cell lymphomas (PTCLs) are a heterogeneous and poorly understood group of aggressive non-Hodgkin lymphomas that develop from mature-stage white blood cells called T-cells and natural killer cells with dismal prognosis.
PTCLs represent a spectrum of T-cell lymphomas and accounts for approximately 10 percent to 15 percent of all NHL cases in the United States. PTCLs include Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), Anaplastic Large-Cell Lymphoma (ALCL), Angioimmunoblastic T-Cell Lymphoma (AITL), Enteropathy-Type T-Cell Lymphoma, Nasal NK/T-Cell Lymphoma, Hepatosplenic Gamma-Delta T-Cell Lymphoma Cutaneous T-cell Lymphomas (CTCL) and others.
PTCL-NOS and AITL and are the most common groups of PTCL accounting for 25% and 18% of all PTCLs, respectively. Additional, less frequent pathologic entities include ALK+ and ALK− anaplastic large cell lymphomas (ALCL), hepatosplenic γδ T-cell lymphomas, enteropathy associated T-cell lymphomas (EATL), nasal type NK-/T-cell lymphomas, panniculitis-like T-cell lymphomas and leukemic forms of PTCL such as HTLV1+ adult T-cell leukemia/lymphoma, T-cell chronic large granular lymphocytic leukemia, aggressive NK-cell leukemia and T-cell prolymphocytic leukemia.
For most subtypes of PTCL, the frontline treatment regimen is typically a combination chemotherapy, such as CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or EPOCH (etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone) or other multi-drug regimens. Because most PTCL patients will relapse, some oncologists recommend giving high-dose chemotherapy followed by an autologous stem cell transplant to some patients who had a good response to their initial chemotherapy program.
Currently a need exists for the early identification of individuals having PTCL in order to offer earlier diagnosis and alternative treatment options. It has been discovered that there is a correlation of certain mutations with the occurrence of PTCL. The identification of these genetic mutations involved in the pathogenesis of and PTCL in screening and diagnostic assays is helpful for early identification and diagnosis of PTCL.